/* * linux/kernel/time/timekeeping.c * * Kernel timekeeping code and accessor functions * * This code was moved from linux/kernel/timer.c. * Please see that file for copyright and history logs. * */ #include <linux/timekeeper_internal.h>#include <linux/module.h>#include <linux/interrupt.h>#include <linux/percpu.h>#include <linux/init.h>#include <linux/mm.h>#include <linux/sched.h>#include <linux/syscore_ops.h>#include <linux/clocksource.h>#include <linux/jiffies.h>#include <linux/time.h>#include <linux/tick.h>#include <linux/stop_machine.h> static struct timekeeper timekeeper; /* * This read-write spinlock protects us from races in SMP while * playing with xtime. */__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); /* flag for if timekeeping is suspended */int __read_mostly timekeeping_suspended; static inline void tk_normalize_xtime(struct timekeeper *tk){ while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) { tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift; tk->xtime_sec++; }} static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts){ tk->xtime_sec = ts->tv_sec; tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift;} static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts){ tk->xtime_sec += ts->tv_sec; tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift; tk_normalize_xtime(tk);} static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm){ struct timespec tmp; /* * Verify consistency of: offset_real = -wall_to_monotonic * before modifying anything */ set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec, -tk->wall_to_monotonic.tv_nsec); WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64); tk->wall_to_monotonic = wtm; set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec); tk->offs_real = timespec_to_ktime(tmp);} static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t){ /* Verify consistency before modifying */ WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64); tk->total_sleep_time = t; tk->offs_boot = timespec_to_ktime(t);} /** * timekeeper_setup_internals - Set up internals to use clocksource clock. * * @clock: Pointer to clocksource. * * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment * pair and interval request. * * Unless you're the timekeeping code, you should not be using this! */static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock){ cycle_t interval; u64 tmp, ntpinterval; struct clocksource *old_clock; old_clock = tk->clock; tk->clock = clock; clock->cycle_last = clock->read(clock); /* Do the ns -> cycle conversion first, using original mult */ tmp = NTP_INTERVAL_LENGTH; tmp <<= clock->shift; ntpinterval = tmp; tmp += clock->mult/2; do_div(tmp, clock->mult); if (tmp == 0) tmp = 1; interval = (cycle_t) tmp; tk->cycle_interval = interval; /* Go back from cycles -> shifted ns */ tk->xtime_interval = (u64) interval * clock->mult; tk->xtime_remainder = ntpinterval - tk->xtime_interval; tk->raw_interval = ((u64) interval * clock->mult) >> clock->shift; /* if changing clocks, convert xtime_nsec shift units */ if (old_clock) { int shift_change = clock->shift - old_clock->shift; if (shift_change < 0) tk->xtime_nsec >>= -shift_change; else tk->xtime_nsec <<= shift_change; } tk->shift = clock->shift; tk->ntp_error = 0; tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; /* * The timekeeper keeps its own mult values for the currently * active clocksource. These value will be adjusted via NTP * to counteract clock drifting. */ tk->mult = clock->mult;} /* Timekeeper helper functions. */static inline s64 timekeeping_get_ns(struct timekeeper *tk){ cycle_t cycle_now, cycle_delta; struct clocksource *clock; s64 nsec; /* read clocksource: */ clock = tk->clock; cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; nsec = cycle_delta * tk->mult + tk->xtime_nsec; nsec >>= tk->shift; /* If arch requires, add in gettimeoffset() */ return nsec + arch_gettimeoffset();} static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk){ cycle_t cycle_now, cycle_delta; struct clocksource *clock; s64 nsec; /* read clocksource: */ clock = tk->clock; cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; /* convert delta to nanoseconds. */ nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); /* If arch requires, add in gettimeoffset() */ return nsec + arch_gettimeoffset();} /* must hold write on timekeeper.lock */static void timekeeping_update(struct timekeeper *tk, bool clearntp){ if (clearntp) { tk->ntp_error = 0; ntp_clear(); } update_vsyscall(tk);} /** * timekeeping_forward_now - update clock to the current time * * Forward the current clock to update its state since the last call to * update_wall_time(). This is useful before significant clock changes, * as it avoids having to deal with this time offset explicitly. */static void timekeeping_forward_now(struct timekeeper *tk){ cycle_t cycle_now, cycle_delta; struct clocksource *clock; s64 nsec; clock = tk->clock; cycle_now = clock->read(clock); cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; clock->cycle_last = cycle_now; tk->xtime_nsec += cycle_delta * tk->mult; /* If arch requires, add in gettimeoffset() */ tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift; tk_normalize_xtime(tk); nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); timespec_add_ns(&tk->raw_time, nsec);} /** * getnstimeofday - Returns the time of day in a timespec * @ts: pointer to the timespec to be set * * Returns the time of day in a timespec. */void getnstimeofday(struct timespec *ts){ struct timekeeper *tk = &timekeeper; unsigned long seq; s64 nsecs = 0; WARN_ON(timekeeping_suspended); do { seq = read_seqbegin(&tk->lock); ts->tv_sec = tk->xtime_sec; nsecs = timekeeping_get_ns(tk); } while (read_seqretry(&tk->lock, seq)); ts->tv_nsec = 0; timespec_add_ns(ts, nsecs);}EXPORT_SYMBOL(getnstimeofday); ktime_t ktime_get(void){ struct timekeeper *tk = &timekeeper; unsigned int seq; s64 secs, nsecs; WARN_ON(timekeeping_suspended); do { seq = read_seqbegin(&tk->lock); secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec; } while (read_seqretry(&tk->lock, seq)); /* * Use ktime_set/ktime_add_ns to create a proper ktime on * 32-bit architectures without CONFIG_KTIME_SCALAR. */ return ktime_add_ns(ktime_set(secs, 0), nsecs);}EXPORT_SYMBOL_GPL(ktime_get); /** * ktime_get_ts - get the monotonic clock in timespec format * @ts: pointer to timespec variable * * The function calculates the monotonic clock from the realtime * clock and the wall_to_monotonic offset and stores the result * in normalized timespec format in the variable pointed to by @ts. */void ktime_get_ts(struct timespec *ts){ struct timekeeper *tk = &timekeeper; struct timespec tomono; s64 nsec; unsigned int seq; WARN_ON(timekeeping_suspended); do { seq = read_seqbegin(&tk->lock); ts->tv_sec = tk->xtime_sec; nsec = timekeeping_get_ns(tk); tomono = tk->wall_to_monotonic; } while (read_seqretry(&tk->lock, seq)); ts->tv_sec += tomono.tv_sec; ts->tv_nsec = 0; timespec_add_ns(ts, nsec + tomono.tv_nsec);}EXPORT_SYMBOL_GPL(ktime_get_ts); #ifdef CONFIG_NTP_PPS /** * getnstime_raw_and_real - get day and raw monotonic time in timespec format * @ts_raw: pointer to the timespec to be set to raw monotonic time * @ts_real: pointer to the timespec to be set to the time of day * * This function reads both the time of day and raw monotonic time at the * same time atomically and stores the resulting timestamps in timespec * format. */void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real){ struct timekeeper *tk = &timekeeper; unsigned long seq; s64 nsecs_raw, nsecs_real; WARN_ON_ONCE(timekeeping_suspended); do { seq = read_seqbegin(&tk->lock); *ts_raw = tk->raw_time; ts_real->tv_sec = tk->xtime_sec; ts_real->tv_nsec = 0; nsecs_raw = timekeeping_get_ns_raw(tk); nsecs_real = timekeeping_get_ns(tk); } while (read_seqretry(&tk->lock, seq)); timespec_add_ns(ts_raw, nsecs_raw); timespec_add_ns(ts_real, nsecs_real);}EXPORT_SYMBOL(getnstime_raw_and_real); #endif /* CONFIG_NTP_PPS */ /** * do_gettimeofday - Returns the time of day in a timeval * @tv: pointer to the timeval to be set * * NOTE: Users should be converted to using getnstimeofday() */void do_gettimeofday(struct timeval *tv){ struct timespec now; getnstimeofday(&now); tv->tv_sec = now.tv_sec; tv->tv_usec = now.tv_nsec/1000;}EXPORT_SYMBOL(do_gettimeofday); /** * do_settimeofday - Sets the time of day * @tv: pointer to the timespec variable containing the new time * * Sets the time of day to the new time and update NTP and notify hrtimers */int do_settimeofday(const struct timespec *tv){ struct timekeeper *tk = &timekeeper; struct timespec ts_delta, xt; unsigned long flags; if (!timespec_valid_strict(tv)) return -EINVAL; write_seqlock_irqsave(&tk->lock, flags); timekeeping_forward_now(tk); xt = tk_xtime(tk); ts_delta.tv_sec = tv->tv_sec - xt.tv_sec; ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec; tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta)); tk_set_xtime(tk, tv); timekeeping_update(tk, true); write_sequnlock_irqrestore(&tk->lock, flags); /* signal hrtimers about time change */ clock_was_set(); return 0;}EXPORT_SYMBOL(do_settimeofday); /** * timekeeping_inject_offset - Adds or subtracts from the current time. * @tv: pointer to the timespec variable containing the offset * * Adds or subtracts an offset value from the current time. */int timekeeping_inject_offset(struct timespec *ts){ struct timekeeper *tk = &timekeeper; unsigned long flags; struct timespec tmp; int ret = 0; if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) return -EINVAL; write_seqlock_irqsave(&tk->lock, flags); timekeeping_forward_now(tk); /* Make sure the proposed value is valid */ tmp = timespec_add(tk_xtime(tk), *ts); if (!timespec_valid_strict(&tmp)) { ret = -EINVAL; goto error; } tk_xtime_add(tk, ts); tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts)); error: /* even if we error out, we forwarded the time, so call update */ timekeeping_update(tk, true); write_sequnlock_irqrestore(&tk->lock, flags); /* signal hrtimers about time change */ clock_was_set(); return ret;}EXPORT_SYMBOL(timekeeping_inject_offset); /** * change_clocksource - Swaps clocksources if a new one is available * * Accumulates current time interval and initializes new clocksource */static int change_clocksource(void *data){ struct timekeeper *tk = &timekeeper; struct clocksource *new, *old; unsigned long flags; new = (struct clocksource *) data; write_seqlock_irqsave(&tk->lock, flags); timekeeping_forward_now(tk); if (!new->enable || new->enable(new) == 0) { old = tk->clock; tk_setup_internals(tk, new); if (old->disable) old->disable(old); } timekeeping_update(tk, true); write_sequnlock_irqrestore(&tk->lock, flags); return 0;} /** * timekeeping_notify - Install a new clock source * @clock: pointer to the clock source * * This function is called from clocksource.c after a new, better clock * source has been registered. The caller holds the clocksource_mutex. */void timekeeping_notify(struct clocksource *clock){ struct timekeeper *tk = &timekeeper; if (tk->clock == clock) return; stop_machine(change_clocksource, clock, NULL); tick_clock_notify();} /** * ktime_get_real - get the real (wall-) time in ktime_t format * * returns the time in ktime_t format */ktime_t ktime_get_real(void){ struct timespec now; getnstimeofday(&now); return timespec_to_ktime(now);}EXPORT_SYMBOL_GPL(ktime_get_real); /** * getrawmonotonic - Returns the raw monotonic time in a timespec * @ts: pointer to the timespec to be set *Lines 1–500 of 1395. Load more
/* * linux/kernel/time/timekeeping.c * * Kernel timekeeping code and accessor functions * * This code was moved from linux/kernel/timer.c. * Please see that file for copyright and history logs. * */ #include <linux/timekeeper_internal.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/percpu.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/sched.h> #include <linux/syscore_ops.h> #include <linux/clocksource.h> #include <linux/jiffies.h> #include <linux/time.h> #include <linux/tick.h> #include <linux/stop_machine.h> static struct timekeeper timekeeper; /* * This read-write spinlock protects us from races in SMP while * playing with xtime. */ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; static inline void tk_normalize_xtime(struct timekeeper *tk) { while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) { tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift; tk->xtime_sec++; } } static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts) { tk->xtime_sec = ts->tv_sec; tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift; } static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts) { tk->xtime_sec += ts->tv_sec; tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift; tk_normalize_xtime(tk); } static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm) { struct timespec tmp; /* * Verify consistency of: offset_real = -wall_to_monotonic * before modifying anything */ set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec, -tk->wall_to_monotonic.tv_nsec); WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64); tk->wall_to_monotonic = wtm; set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec); tk->offs_real = timespec_to_ktime(tmp); } static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t) { /* Verify consistency before modifying */ WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64); tk->total_sleep_time = t; tk->offs_boot = timespec_to_ktime(t); } /** * timekeeper_setup_internals - Set up internals to use clocksource clock. * * @clock: Pointer to clocksource. * * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment * pair and interval request. * * Unless you're the timekeeping code, you should not be using this! */ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) { cycle_t interval; u64 tmp, ntpinterval; struct clocksource *old_clock; old_clock = tk->clock; tk->clock = clock; clock->cycle_last = clock->read(clock); /* Do the ns -> cycle conversion first, using original mult */ tmp = NTP_INTERVAL_LENGTH; tmp <<= clock->shift; ntpinterval = tmp; tmp += clock->mult/2; do_div(tmp, clock->mult); if (tmp == 0) tmp = 1; interval = (cycle_t) tmp; tk->cycle_interval = interval; /* Go back from cycles -> shifted ns */ tk->xtime_interval = (u64) interval * clock->mult; tk->xtime_remainder = ntpinterval - tk->xtime_interval; tk->raw_interval = ((u64) interval * clock->mult) >> clock->shift; /* if changing clocks, convert xtime_nsec shift units */ if (old_clock) { int shift_change = clock->shift - old_clock->shift; if (shift_change < 0) tk->xtime_nsec >>= -shift_change; else tk->xtime_nsec <<= shift_change; } tk->shift = clock->shift; tk->ntp_error = 0; tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; /* * The timekeeper keeps its own mult values for the currently * active clocksource. These value will be adjusted via NTP * to counteract clock drifting. */ tk->mult = clock->mult; } /* Timekeeper helper functions. */ static inline s64 timekeeping_get_ns(struct timekeeper *tk) { cycle_t cycle_now, cycle_delta; struct clocksource *clock; s64 nsec; /* read clocksource: */ clock = tk->clock; cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; nsec = cycle_delta * tk->mult + tk->xtime_nsec; nsec >>= tk->shift; /* If arch requires, add in gettimeoffset() */ return nsec + arch_gettimeoffset(); } static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) { cycle_t cycle_now, cycle_delta; struct clocksource *clock; s64 nsec; /* read clocksource: */ clock = tk->clock; cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; /* convert delta to nanoseconds. */ nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); /* If arch requires, add in gettimeoffset() */ return nsec + arch_gettimeoffset(); } /* must hold write on timekeeper.lock */ static void timekeeping_update(struct timekeeper *tk, bool clearntp) { if (clearntp) { tk->ntp_error = 0; ntp_clear(); } update_vsyscall(tk); } /** * timekeeping_forward_now - update clock to the current time * * Forward the current clock to update its state since the last call to * update_wall_time(). This is useful before significant clock changes, * as it avoids having to deal with this time offset explicitly. */ static void timekeeping_forward_now(struct timekeeper *tk) { cycle_t cycle_now, cycle_delta; struct clocksource *clock; s64 nsec; clock = tk->clock; cycle_now = clock->read(clock); cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; clock->cycle_last = cycle_now; tk->xtime_nsec += cycle_delta * tk->mult; /* If arch requires, add in gettimeoffset() */ tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift; tk_normalize_xtime(tk); nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); timespec_add_ns(&tk->raw_time, nsec); } /** * getnstimeofday - Returns the time of day in a timespec * @ts: pointer to the timespec to be set * * Returns the time of day in a timespec. */ void getnstimeofday(struct timespec *ts) { struct timekeeper *tk = &timekeeper; unsigned long seq; s64 nsecs = 0; WARN_ON(timekeeping_suspended); do { seq = read_seqbegin(&tk->lock); ts->tv_sec = tk->xtime_sec; nsecs = timekeeping_get_ns(tk); } while (read_seqretry(&tk->lock, seq)); ts->tv_nsec = 0; timespec_add_ns(ts, nsecs); } EXPORT_SYMBOL(getnstimeofday); ktime_t ktime_get(void) { struct timekeeper *tk = &timekeeper; unsigned int seq; s64 secs, nsecs; WARN_ON(timekeeping_suspended); do { seq = read_seqbegin(&tk->lock); secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec; } while (read_seqretry(&tk->lock, seq)); /* * Use ktime_set/ktime_add_ns to create a proper ktime on * 32-bit architectures without CONFIG_KTIME_SCALAR. */ return ktime_add_ns(ktime_set(secs, 0), nsecs); } EXPORT_SYMBOL_GPL(ktime_get); /** * ktime_get_ts - get the monotonic clock in timespec format * @ts: pointer to timespec variable * * The function calculates the monotonic clock from the realtime * clock and the wall_to_monotonic offset and stores the result * in normalized timespec format in the variable pointed to by @ts. */ void ktime_get_ts(struct timespec *ts) { struct timekeeper *tk = &timekeeper; struct timespec tomono; s64 nsec; unsigned int seq; WARN_ON(timekeeping_suspended); do { seq = read_seqbegin(&tk->lock); ts->tv_sec = tk->xtime_sec; nsec = timekeeping_get_ns(tk); tomono = tk->wall_to_monotonic; } while (read_seqretry(&tk->lock, seq)); ts->tv_sec += tomono.tv_sec; ts->tv_nsec = 0; timespec_add_ns(ts, nsec + tomono.tv_nsec); } EXPORT_SYMBOL_GPL(ktime_get_ts); #ifdef CONFIG_NTP_PPS /** * getnstime_raw_and_real - get day and raw monotonic time in timespec format * @ts_raw: pointer to the timespec to be set to raw monotonic time * @ts_real: pointer to the timespec to be set to the time of day * * This function reads both the time of day and raw monotonic time at the * same time atomically and stores the resulting timestamps in timespec * format. */ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) { struct timekeeper *tk = &timekeeper; unsigned long seq; s64 nsecs_raw, nsecs_real; WARN_ON_ONCE(timekeeping_suspended); do { seq = read_seqbegin(&tk->lock); *ts_raw = tk->raw_time; ts_real->tv_sec = tk->xtime_sec; ts_real->tv_nsec = 0; nsecs_raw = timekeeping_get_ns_raw(tk); nsecs_real = timekeeping_get_ns(tk); } while (read_seqretry(&tk->lock, seq)); timespec_add_ns(ts_raw, nsecs_raw); timespec_add_ns(ts_real, nsecs_real); } EXPORT_SYMBOL(getnstime_raw_and_real); #endif /* CONFIG_NTP_PPS */ /** * do_gettimeofday - Returns the time of day in a timeval * @tv: pointer to the timeval to be set * * NOTE: Users should be converted to using getnstimeofday() */ void do_gettimeofday(struct timeval *tv) { struct timespec now; getnstimeofday(&now); tv->tv_sec = now.tv_sec; tv->tv_usec = now.tv_nsec/1000; } EXPORT_SYMBOL(do_gettimeofday); /** * do_settimeofday - Sets the time of day * @tv: pointer to the timespec variable containing the new time * * Sets the time of day to the new time and update NTP and notify hrtimers */ int do_settimeofday(const struct timespec *tv) { struct timekeeper *tk = &timekeeper; struct timespec ts_delta, xt; unsigned long flags; if (!timespec_valid_strict(tv)) return -EINVAL; write_seqlock_irqsave(&tk->lock, flags); timekeeping_forward_now(tk); xt = tk_xtime(tk); ts_delta.tv_sec = tv->tv_sec - xt.tv_sec; ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec; tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta)); tk_set_xtime(tk, tv); timekeeping_update(tk, true); write_sequnlock_irqrestore(&tk->lock, flags); /* signal hrtimers about time change */ clock_was_set(); return 0; } EXPORT_SYMBOL(do_settimeofday); /** * timekeeping_inject_offset - Adds or subtracts from the current time. * @tv: pointer to the timespec variable containing the offset * * Adds or subtracts an offset value from the current time. */ int timekeeping_inject_offset(struct timespec *ts) { struct timekeeper *tk = &timekeeper; unsigned long flags; struct timespec tmp; int ret = 0; if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) return -EINVAL; write_seqlock_irqsave(&tk->lock, flags); timekeeping_forward_now(tk); /* Make sure the proposed value is valid */ tmp = timespec_add(tk_xtime(tk), *ts); if (!timespec_valid_strict(&tmp)) { ret = -EINVAL; goto error; } tk_xtime_add(tk, ts); tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts)); error: /* even if we error out, we forwarded the time, so call update */ timekeeping_update(tk, true); write_sequnlock_irqrestore(&tk->lock, flags); /* signal hrtimers about time change */ clock_was_set(); return ret; } EXPORT_SYMBOL(timekeeping_inject_offset); /** * change_clocksource - Swaps clocksources if a new one is available * * Accumulates current time interval and initializes new clocksource */ static int change_clocksource(void *data) { struct timekeeper *tk = &timekeeper; struct clocksource *new, *old; unsigned long flags; new = (struct clocksource *) data; write_seqlock_irqsave(&tk->lock, flags); timekeeping_forward_now(tk); if (!new->enable || new->enable(new) == 0) { old = tk->clock; tk_setup_internals(tk, new); if (old->disable) old->disable(old); } timekeeping_update(tk, true); write_sequnlock_irqrestore(&tk->lock, flags); return 0; } /** * timekeeping_notify - Install a new clock source * @clock: pointer to the clock source * * This function is called from clocksource.c after a new, better clock * source has been registered. The caller holds the clocksource_mutex. */ void timekeeping_notify(struct clocksource *clock) { struct timekeeper *tk = &timekeeper; if (tk->clock == clock) return; stop_machine(change_clocksource, clock, NULL); tick_clock_notify(); } /** * ktime_get_real - get the real (wall-) time in ktime_t format * * returns the time in ktime_t format */ ktime_t ktime_get_real(void) { struct timespec now; getnstimeofday(&now); return timespec_to_ktime(now); } EXPORT_SYMBOL_GPL(ktime_get_real); /** * getrawmonotonic - Returns the raw monotonic time in a timespec * @ts: pointer to the timespec to be set *